--- old/src/java.base/share/classes/java/nio/charset/UnmappableCharacterException.java	2019-08-27 17:28:08.886324386 -0700
+++ new/src/java.base/share/classes/java/nio/charset/UnmappableCharacterException.java	2019-08-27 17:28:08.698324386 -0700
@@ -38,6 +38,7 @@
     extends CharacterCodingException
 {
 
+    @java.io.Serial
     private static final long serialVersionUID = -7026962371537706123L;
 
     private int inputLength;